Gear cutter



April 24, 1928. 1,667,299 E. WILDHABER GEAR CUTTER Filed March 16, 1927 I5 I, By 2 E II/III!! 24 24 2o Q 0 Fig.3 I7 I {7 v 17 E t V /adlza be mes 1' 5 I 7 9 6 '24 ATTORNE$ Patented Apr. 24, 1928.

UNITED ROCHESTER, NEWYIYQBKI, A ooitPoRArIon OIMNEW Yuan;

GE AR ame; I

A lication filed March 19, 1925 s riaino: 175,359.

The present invention relates to gear cutters for cutting longitudinallycurved{tooth gears and particularly togear cutters'of the general type described in'U. S. Letters Patent No. 1,236,834, Gleason, AugustM, 1917. i

l The primaryobject ofthis' invention is to'provide acutting blade which Will have two side cutting edges capable ofsimulta'ne ously finish cutting two adjacent side" tooth faces of a longitudinally curyed toothgear. Otherwise stated, the=present invention' has for its purpose to provide a: forinof cutting blade, adapted forlcutting spira lor longitudinally curved tooth gears, which will have two side cutting edges each capable of taking a smooth out on a tooth surface of a: gear blank during the curvilinear'movement of the blade.

In the drawingsz Figures 1 and 2 are a plan viewand side elevation, respectively showing the relative positions of a cutter constructed according to the preferred embodiment'of my invention and aytaperedcutting operation; p I, a y p Figure 3 is an enlarged side yietv ofione of the cutting blades;" i 1 f Figure 4 is a perspective viewof one form of blade constructed according to this invention; and y Figures '5 and G are a plan or end View and a perspective view. respectively, showgear blank 5 during f the ing a modified form of cutting blade contructed according tothis invention. I p

The cutter commonly employed in cutting curved tooth gearstwo side faces simultaneously has finish side cuttingjedges'lon alternate blades. The blades a re provided *With a side rake, alternate blades having the side sidcsof alternate blades. 'The cutting' edges of the blades of this form of cutterlie'in planes which pass'through the cutter 'a'xis and are perpendicular to the face of the cutter head. f 7 "if It has also been prop osedfto linakeljthe rut-ting bladeswithout side rakeand progranted to James vide twof cutting edges on each blade. Here again-the cutting edges lie in. planes per pendicular to the" facejof thebu'tter head. The cutting action of blades constructed in the manner last described, however, is poor and the} tooth surface finish is not smooth.

:Theu'iurpose of Ithe'ipresent invention i's to provide a form of. cutter blade which may have two tinish side cutting edges and still cut as smoothly. as do cutters constructed: accordiiig to the first form described. The aim offithis invention, hence,-is toipro'vide a gear cutter which will speed'upproduction while at the same time cutting tooth surfaces of the desired quality. i

In. the preferred form of" this invention, thecutting blades are provided with a front rake, [that is, the cutting edges a-reinclined rearwardly from the tipor end of'the cutting portion-of the blade tothe body :portionfthereof. H'This Will 'givc each side cut ting edge of the blade a: good cutting action and-each Isidecutting edge may become therefore, a finish side cutting edge, thereby .videchvvith a front rake, butits front face is concavedfr om side to side. If the con cavity of the front ffacehisfkept Within reasonable limits,-it has been found that this defines the sidecutting edges more sharply makes their cutting action keener. Both modifications are shownyin the accompanying drawings; It will :be understood, however that the invent-ion is ca able of liln'itsof the appended claims further modification within its scope and the In Figures 1 and 2,21 rotary annular face rake extendlng 1n opposite directions, thus throwing the finlsh' cutting edge to opposite mill 1O,1fsuch as is commonly employed in cuttingspiral orlongltudinally curved toot h gears, issho'wn r0v1ded Wltli a plurality of cutting blades 11 constructed according to t "thIS ID YGHtIOHI The -face"n'nlil has a; head or support 12tv-hichj is adapted to 'be mounted and a cutting portion 18 on which the.cut-

ting edges are formed. The cutting portion 18 comprises a front face 19, two side faces 20, a back face'21 and an end or top face 22.

The cutting portion is provided with a front rake or hook, that is. the front face 19 is inclined rearwardly from the end :or

Q tip 22 to the body portion 17. The front face 19 forms/with the side faces 20 two-side cutting edges ,24 and-with theend face22, an end cutting edge 25.

Each of the side cutting edges 24 is inclined rearwardly from the end cuttingzedge 25. 'VVhenassembled on the cutter head-the cutting-edges lie in a plane :whichisinclined to:the face of thecutter head.

When a cutting blade is constructed rin the manner described. each of the side cutting edges willtakea clea=n,-sharp cut. Consequently, each blade may have two side finish cutting edges, each capable of. cutting a tooth surface of the-blank with the required smoothness.

The sides 20 are curved longitudinally from frontto back and relieved with-reference to the front cuttingedges to provide'the necessar) clearance for the cutting edges during the zCllt-. Similarly, the end :face '22 is relieved with reference to the end cutting edge .25 The side cutting faces'may be'relieved on any desired curve. In practise, the side cutting faces areof helicalform with reference to the rotary axis 14 of'the cutter head.

The front face 19 of the cutting portion may be a plane, as shown'in Figure i, or a 'concavesurface as showndn Figures 5 and 6 at 19. give better results, as the concavity of the front face sharply defines the side cutting In certain 'cases. the latter "form will edges 24 and improves their cutting action. there the front face is made concave, the cutting portion will be provided, preferably nonetheless. with a front rake as before; In

either modification, the front face of the blade will be inclined preferably in such manner that eitherthe two end points'of the side cutting edges or the two points in the two side-cutting adges which operate at the pitch lines of the tooth faces of the gear blank .lie in a line extending radially from the axis of the cutterhead.

In Figuresl and 2, a face mill 10, con- 'structed according to this invention, isshown in ocuttingengagement Wlllll a tapered gear blank 28. As the *face mill rotates on its axis, thecuttingwedges will move in a circle, each blade being brought successively into cutting engagement with the blank and each cutting bladewill take simultaneously a finishing out upon the two adjacent side tooth faces of the blank defining a groove thereof. With this invention, the cutting operation can be completed more rapidly, while meeting present day requirements as to smoothnessand quality of tooth surface finish.

,A cutter constructed according to the present invention will preferably be employed as a finishing tool, operating upon a blank which has been previously roughed out, though, if desired, the cutter may be used to :rough out andfinish cut. Gears may be cut in a generating or non-generating (formed) operation with a tool constructed according to this invention.- The. side cuttiiigiedgcs may-he made straight or curved, as required. The cutting edges, will of course, have a pressure angle; determined by the, usual methods. a

Tools+constructed according, to this invention may be employed incutting longitudinall curved toot-h sur gears as well as longitudinally curved tooth tapered gears, both bevel and ;hypoid.-

While 'theinvention has been shown as applied-to a rotary annular face mill, it will he:understood.:that the tool might be a face hobbing cutter in which the blades are so arrangedkasto cut in successive-tooth spaces of the blank.

The invention ,is capable .of further modification also. In general, it may be said, that this application is. intended to cover any variations, uses, or adaptations'of my invention, following, .in general, the :principles of the invention and including such departures from the present disclosure :as. come Wlthlll known or customary practise in the gear art and as may beapplied to the essential zfeatures hereinbefore set forth and as fall within the SCOPG'Of the invention or the i-limits of the appended claims.

Having thus described any invention, 'wh a t I claim 1s:

:1. Agear cutter blade having acutting portionprovided-with front, cnd,.side,-and back faces, the'ifr'ont 'facebeing concave and forming with the side faces and end face two side andan end cutting edge, said side faces being curved longitudinally from front to .back, said side faces and end face being relieved with reference to said cutting edges. 2. .A gear; cutter blEIClPCOHIPIISIHQ abody portion and a cutting portion, said cutting portion being-provided with frontaend. side and back faces, the front *face being inclined rearwardly from the end face to said body portionand forming withthe side faces and end face two rearwardly'inclined side cutting edges and an end cutting edge, said side faces being curved longitudinally from front to back, and :said' side faces. andend face being relieved with reference to said cutting edges".

portionand a cutting porti'on, said cutting portion being provided with. front, end, side and back faces, said front facebeing concave and inclined rearwardly from tIie end face tosaid body portion and foriningwitli the side faces and end face, a pair of rearwardly inclined side cutting edges and an end cutting edge, said side faces being curved longitudinally from front toback, said side faces and end face being relieved with reference to said cutting edges. a i

' 4. A gear cutter comprising a hcadadapted to be rotated and carrying aplui'ality of cutting blades, each of said cutting blades having a cutting portion projecting from said head in the general direction of the axis of said head and provided with front, end, side and back faces, the front facebeing concave from side to side and forming with the side faces and end face a pair of side. cutting; edges andan end "cutting edge, said side'faces being curved longitudinally from front to back and Stud side faces and end face being relieved withreference to said cutting edges. a

5. A gear cutter coniprismg a head adapted to be rotated and carrying a plurality of cutting blades, each of said cutting bladeshaving a cutting portion pro ecting from said head in the general direction of tlieaxis of said 'head and providedwith front, end, side and back faces, said front facebeing inclined to said head and forming with said end and side faces an end cutting edge and two side cutting ed es, said side faces being curved longitudinally from front to back and said side and end faces being relieved with reference to said cutting edges.

.6. A gear cutter comprising a head adapt ed to 'be rotated and carryinga plurality of cutting blades, each of saidcuttirig blades having a cutting portion projecting from said head in the general direction oftlic axis of said head and provided with front, end,

side and back faces, said .f'ront face being concave from sideto side and inclined rearwardly fronithe end face and forming with said sides and end facesan end cutting edge and two side cutting edges,,said side faces being curvedlongitudinally froni-front to back and said, side and end faces being relieved with reference to said cutting edges.

7. A gear cutter blade provided With front, side, end, and back faces, the front face being inclined rearwardly frointhe end face and forming with a side face a side cutting edge, said side face being curved longitudinally from front to back and being relieved with reference to said side cutting edge. 8.1K gear cutter blade provided with front, side, end and back faces, thefi'ont f ace being concave from side to side, forining with a side face a side outting edge,

will contain .said side face being curvedlongitudinally froin frontto back and being relieved with rcferenceto said side cutting edge. 9. A' gear cutter: blade having a cutting portion provided with front, end, side and back faces, said sidei faces being curved longitudinally from front to back, said front face forniingan acute angle with each side face to provide-inside and outside finish portion and forming an acute anglewith each side face to provide inside and outside finish cutting edges, said side faces being curved longitudinally from front to back and being relieved with reference to said finish cutting edges.

11. A gear cutter comprising al head adapted to be rotated and carrying'a pluralityof cutting blades, each of said cutting blades having acutting portion projecting flOID said head in the general direction. of the axis of said head, Stt1(l0l1ttll]g portions being provided with front, end, side and back faces, the front face of each blade foriniiigan acute angle with its side faces, whereby each blade is provided with inside and outside finish cutting edges, the side faces of each blade bGIDgIGhQ BCl with reference to its finish cutting edges, said blades being of equal width in a plane perpendicular to the axis of the tool and correspondin side cuttin edges of the blades being equa 9 u b 0 ly inclinedto said plane. w i t 12. A gear cutter compr sing a head adapted to be rotated and carrying a plurality ofcutting blades, each of said'cutting blades havinga cutting portionprojecting fIOIlI said head inthe'general directionof the axis of said head, saidcutting portionsbeingpi'ovided with front, end, side, and.

back faces, the front face of each blade foi'niingan acute anglewithIitsside faces,

whereby each blade is provided with inside and outside finishcutting edges, the side faces of each blade beingrelieved with reference to said finish cutting edges, said blades beingof equal Width in aplaneperpendicular to the axis of the tool and corresponding side cutting edges of said blades being equal ly inclined to said plane, eaclrof saidblades being. sopositioned onthe head that a line drawn radially from the axis of the head points onthe opposite sideciitting edges; 1

A gear cutter "comprising a head adapted to berotated and carrying a plurality of cutting blades, each of saidcutting blades having a cutting portion projecting from said head in the general direction of the axis of said head, said cutting portions being providedwith front, .end, side and back faces, the front face of each blade being "inclinedrearwardly from its end face to said head and forming an acute angle with its side faces whereby each blade is provided with inside and outside finish cutting edges, the side faces of arch blade being relieved with reference to its finish cutting edges, said blades being of equal width in a plane perpendicular to the axis of the tool and corresponding side cutting edges of the blades being equally inclined to said plane.

l4. A gear cutter comprising a head adapted to be rotated and carrying a plurality of cutting blades, each of said cutting blades having a cutting portion projecting from said head in the general direction of the axis of said head, said cutting portions being provided with front, end, side and back .faees,the front face of each bladebeing inclined rearwardly from its end face to said head and fornung an acute angle with its side faces whereby each blade is provided with insideand outside finish cutting edges,the side faces of each blade being relieved with reference to said finish cutting edges, said blades being of equal width in a plane perpendicular to the axis of the tool.

and corresponding side cutting edges being equally inclined to said plane, each blade being so positioned on the head that a line drawn radially from the axis of the head willcontain points on the opposite side cutting edges.

15. A gear cutter comprising a head adapted to be rotated and carrying a plurality of cutting blades, each of said cutting blades having a cutting portion projecting froin said head in the general direction of the axis of said head and provided with front, end, side, and back faces, the front face of each blade being concave from-side to side and forming with the side faces and end face a pair of side cutting edges and an end cutting edge, said side faces and end face being relieved with reference to, said cutting edges, each of said blades being of equal width in a plane perpendicular to the axis of the tool and corresponding side cutting edges of the blades being equally inclined to said plane.

16. A gear cutter comprising a head adapted to be rotated and carrying a plurality of cutting blades, each of said cutting blades having a cutting portion projecting from said head in the general direction of the axis of said head and provided with front, endrside, and back faces, said front face being inclined to said head and forming with said head and side faces an end cutting edge and .two side cutting edges, said side and end faces being relieved with reference to said cutting edges, said blades being of equal width in a plane perpendicular to the axis of the toolvand corresponding side cutting edgesofthe blades being equally inclinedto edge and two side cutting edges,-said side and'end faces'being'relieved with reference to said cutting edges, said blades being of equal width in a plane perpendicular to the axis of the tool and corresponding side cutting edges of the blades being equally inclined to said plane.

18. A gear cutter comprising ahead adapted to be.rot-ated and carrying a plurality of cutt-ingblades, each of said cutting blades having a cutting portion projecting from said head. in the general direction of the axis of said head and provided with front, end, side, and backfaces, said frontfacebeing concave from side to side and forming with the side facesand end face a pair of side cutting edges and an end cutting edge, each I of said blades being so positioned on the head that, a line drawn-radially from the axis of thehead will contain points on opposite side cutting edges, said bladesbeing of equal width in a plane vperpendicular to the axis of the tool and corresponding side cutting edges of the blades being equally inclined to said plane.

19. A gear cutter comprising a head adapted to be rotated and carrying a plurality of cutting blades, each of said cutting blades having a cutting portion projecting flOlIl StllCl head in the general direction of the axis of said head and provided with front, end, side and back faces, said front face being inclined rearwardly from said end face toward said head andforining with the side faces and end face a pair of side cutting edges and an end cutting edge, each of said blades being so positioned on the headthat a line drawn radially from the axis of the head will contain points on opposite side cutting edges, said blades being of equal width in a :plane perpendicular to the'axis of the tool and corresponding side cutting edges of the blades being equally inclined to said plane.

20. A gear cutter comprising a head adapted'to be rotated and carrying a plurality of cutting blades, each of said cutting blades having a cutting portion projecting from said head in the general direction of the axis of said head and provided with front, end, side, and back faces, said front face being concave -from .-side'to sideand in- 1,667,200 I cu clined rearwardly fromthe end face toward ting edges, said blades being of equal width said head and forming with the side faces in a plane perpendicular to the axis of the and end face a pair of side cutting edges and head and corresponding side cutting edges 10 an end cutting edge, each of said blades beof the blades being equally inclined to said ing so positioned on the head that a line plane. drawn radially from the axis of the head will contain points on the opposite side cut- I ERNEST WILDHABER. 

